<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script type="text/javascript">
    var arr=[];
    for(var i=0;i<4;++i){
        arr[i]=function(){
            console.log(i);
        }
    }
    arr[0]();
    arr[1]();
    arr[2]();
    arr[3]();

</script>
</body>
</html>